RPGs with attribute systems pretty much always have fixed scores that go up with exp and, maybe, down with age. This is a poor simulation of real life, and doesn’t allow for stories like The Incredibles that feature getting back into shape as part of the narrative. The system below is probably more bookkeeping than it’s worth for most, and may be a fight with players who only want the numbers to go up, but allows telling stories where the capabilities of the heroes wax and wane as their situation demands. It’s meant for stories with long downtimes where the PCs aren’t so much adventurers that are constantly in action as they are heroes that step up when they’re needed.

Core Ability Scores

No matter how much the scores shift, keep track of the ability scores the PCs started with (modified by race, age, level increase, and inherent bonuses). It’s easier to return to these scores despite increases or decreases.

If you rolled scores randomly to start, you can instead assign point-buy totals or an array as these core ability scores. In that way, the random rolling may have favored certain players at the beginning, but those high scores represent a lot of workout in advance and have to be maintained, while lower-than-average rollers have an easy time advancing once they get into the heroic lifestyle.

Whenever you are under your core ability score, it takes two marks to require a roll to decrease. Whenever you are above your core ability score, it takes two marks to allow a roll to increase.


Figure out what a standard longish downtime is for your game. A year is a good start, but if you’re rarely going to have that much downtime, set it to six months or even a month. If you regularly have more (e.g., your PCs are all elves), increase the length.

At the end of each such downtime period, make a decrease mark on all ability scores. Any score with an increase mark has a mark erased instead of adding a decrease mark.

During the downtime, each PC can take up to 12 increase marks representing working to keep in shape on particular ability scores (physical workouts for Strength, Dexterity, and Constitution, and more academic or social workouts for Intelligence, Wisdom, and Charisma). Those marks are instead of other downtime actions that could be taken in the same time period (for a standard one-year downtime, each mark represents a month not spent on other system-based activities like rolling skills to earn money). You can gloss the fiction as desired (e.g., a character that took six increase marks and six months of skill checks may have been working full time, but only half as effectively due to time spent keeping in shape).

Adventure and Imprisonment

On adventures, the GM may award bonus increase marks as additional rewards, possibly even assigning them directly based on actions (e.g., “For passing the ordeals, everyone gets an increase mark on Con” instead of just giving out a mark in anything).

If the characters are imprisoned for long periods, they gain decrease marks at double the normal rate. If they’re imprisoned in a small space with limited mobility, they gain decrease marks at triple the normal rate. Fortunately, they probably have few other duties, so can use most of their time to try to cancel out these marks.

Increasing and Decreasing

At the end of a downtime period, make rolls to see if your scores changed. For both increasing and decreasing, roll 4d6 (drop lowest; or 3d6 if you’re old school) plus mods (racial, age, level increase, and inherent).

  • If you have any decrease marks, make a roll for each (or a roll for every two if you’re below your core score). If you roll less than your current total, it decreases by one.
  • If you have any increase marks, make a roll for each (or a roll for every two if you’re above your core score). If you roll more than your current total, it increases by one.

Erase all the marks you rolled for. Any left over (such as ones requiring two to increase or decrease) remain until the end of the next downtime.

Changing Intelligence doesn’t change skill points (use your core score for this), but does change its bonus to things.